A synthetic peptide based on a glycine-gated chloride channel induces a novel chloride conductance in isolated epithelial cells.
A synthetic peptide based on a glycine-gated chloride channel induces a novel chloride conductance in isolated epithelial cells.
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基于甘氨酸门控氯离子通道的合成肽在分离的上皮细胞中诱导新型氯离子电导。
DOI：
10.1016/s0005-2736(00)00170-x
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Freeman,LC
中科院分区：
文献类型：
--
作者：
Mitchell,KE;Iwamoto,T;Tomich,J;Freeman,LC
CK4-M2GlyR是一种水溶性多肽，来源于中枢神经系统突触后膜甘氨酸门控CL-−通道的跨膜M2段，已有研究表明它能增加跨上皮CL-−和上皮单层液体的分泌。本研究的目的是确定CK4-M2GlyR是否通过形成新的氯离子电导途径、调节内源性氯离子通道活性或这些作用的组合来发挥这些作用。用膜片钳技术的全细胞构型记录多肽处理前后分离的上皮细胞的离子电流。CK4-M2GlyR增加了所有被研究的上皮细胞系的全细胞CL-−电流，包括：马丁达比犬肾细胞，人结肠上皮细胞系(T84)，以及来自人囊性纤维化患者的呼吸道上皮细胞(IB3-1)。根据观察电流的电生理特性和CK4-M2GlyR诱导电流的药理学特征，没有证据表明CK4-M2GlyR对内源性Cl-−通道的调节。这些结果表明，CK4-M2GlyR通过在细胞膜上形成明显的传导途径，直接增加上皮细胞的Cl-−通透性。
CK4-M2GlyR, an aqueous soluble peptide derived from the transmembrane M2 segment of the glycine-gated Cl−channel found in postsynaptic membranes of the central nervous system, has previously been shown to increase transepithelial Cl−and fluid secretion of epithelial monolayers. The goal of this study was to determine whether CK4-M2GlyR exerts these effects via formation of a novel chloride conductance pathway, modulation of endogenous chloride channel activity, or a combination of these effects. Ionic currents were recorded from isolated epithelial cells before and after treatment with the peptide using the whole-cell configuration of the patch-clamp technique. CK4-M2GlyR increased whole-cell Cl−currents in all epithelial cell lines that were studied, including: Madin–Darby canine kidney cells, a human colonic epithelial cell line (T84), and airway epithelial cells derived from a human cystic fibrosis patient (IB3-1). No evidence was found for modulation of endogenous Cl−channels by CK4-M2GlyR based on both the electrophysiological properties of the observed currents and the pharmacological profile of the CK4-M2GlyR-induced current. These results suggest that CK4-M2GlyR increases Cl−permeability in epithelial cells directly, by forming a distinct conduction pathway in cell membranes.